Head-up displays (HUDs) are becoming increasingly popular in the aerospace industry. Known HUDs typically include at least a projector, a combiner, and an image generator. The projector receives images supplied from the image generator, and the HUD will typically include an optical collimator, such as a convex lens or concave mirror, to produce an image that is perceived to be at or near infinity.
The combiner reflects the image projected by the projector in such a way as to see the field of view and the projected infinity image at the same time. The combiner is typically a very precisely designed and controlled optical element and may be flat or curved. Some combiners may also have special coatings that reflect certain wavelengths of light projected onto it from the projector while allowing all other wavelengths of light to pass through.
Traditional prior art HUDs typically rely on sophisticated optics to meet the performance requirements for avionic use. These performance requirements include precise angular control and uniformity over an exit pupil or head box that is large enough to encompass both eyes of a pilot or other user. As an example, the size, weight and cost of a bulky overhead unit (OHU) may be driven to a large extent by the required performance levels.
One known HUD, described in U.S. application Ser. No. 14/102,950 assigned to the assignee of the present invention, provides separately corrected images to each eye by forming separate eyeboxes for the right eye and the left eye.
Hence, there is a need for a HUD that does not rely upon sophisticated optics to meet the performance requirements needed for use in avionics environments. The present invention addresses at least this need. Furthermore, other desirable features and characteristics of the exemplary embodiments will become apparent from the subsequent detailed description and the appended claims, taken in conjunction with the accompanying drawings and the foregoing technical field and background.